xref: /linux/drivers/phy/phy-spacemit-k1-pcie.c (revision c17ee635fd3a482b2ad2bf5e269755c2eae5f25e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SpacemiT K1 PCIe and PCIe/USB 3 combo PHY driver
4  *
5  * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/iopoll.h>
12 #include <linux/kernel.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/module.h>
15 #include <linux/phy/phy.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 #include <linux/reset.h>
19 
20 #include <dt-bindings/phy/phy.h>
21 
22 /*
23  * Three PCIe ports are supported in the SpacemiT K1 SoC, and this driver
24  * supports their PHYs.
25  *
26  * The PHY for PCIe port A is different from the PHYs for ports B and C:
27  * - It has one lane, while ports B and C have two
28  * - It is a combo PHY can be used for PCIe or USB 3
29  * - It can automatically calibrate PCIe TX and RX termination settings
30  *
31  * The PHY functionality for PCIe ports B and C is identical:
32  * - They have two PCIe lanes (but can be restricted to 1 via device tree)
33  * - They are used for PCIe only
34  * - They are configured using TX and RX values computed for port A
35  *
36  * A given board is designed to use the combo PHY for either PCIe or USB 3.
37  * Whether the combo PHY is configured for PCIe or USB 3 is specified in
38  * device tree using a phandle plus an argument.  The argument indicates
39  * the type (either PHY_TYPE_PCIE or PHY_TYPE_USB3).
40  *
41  * Each PHY has a reset that it gets and deasserts during initialization.
42  * Each depends also on other clocks and resets provided by the controller
43  * hardware (PCIe or USB) it is associated with.  The controller drivers
44  * are required to enable any clocks and de-assert any resets that affect
45  * PHY operation.  In addition each PHY implements an internal PLL, driven
46  * by an external (24 MHz) oscillator.
47  *
48  * PCIe PHYs must be programmed with RX and TX calibration values.  The
49  * combo PHY is the only one that can determine these values.  They are
50  * determined by temporarily enabling the combo PHY in PCIe mode at probe
51  * time (if necessary).  This calibration only needs to be done once, and
52  * when it has completed the TX and RX values are saved.
53  *
54  * To allow the combo PHY to be enabled for calibration, the resets and
55  * clocks it uses in PCIe mode must be supplied.
56  */
57 
58 struct k1_pcie_phy {
59 	struct device *dev;		/* PHY provider device */
60 	struct phy *phy;
61 	void __iomem *regs;
62 	u32 pcie_lanes;			/* Max (1 or 2) unless limited by DT */
63 	struct clk *pll;
64 	struct clk_hw pll_hw;		/* Private PLL clock */
65 
66 	/* The remaining fields are only used for the combo PHY */
67 	u32 type;			/* PHY_TYPE_PCIE or PHY_TYPE_USB3 */
68 	struct regmap *pmu;		/* MMIO regmap (no errors) */
69 };
70 
71 #define CALIBRATION_TIMEOUT		500000	/* For combo PHY (usec) */
72 #define PLL_TIMEOUT			500000	/* For PHY PLL lock (usec) */
73 #define POLL_DELAY			500	/* Time between polls (usec) */
74 
75 /* Selecting the combo PHY operating mode requires APMU regmap access */
76 #define SYSCON_APMU			"spacemit,apmu"
77 
78 /* PMU space, for selecting between PCIe and USB 3 mode (combo PHY only) */
79 
80 #define PMUA_USB_PHY_CTRL0			0x0110
81 #define COMBO_PHY_SEL			BIT(3)	/* 0: PCIe; 1: USB 3 */
82 
83 #define PCIE_CLK_RES_CTRL			0x03cc
84 #define PCIE_APP_HOLD_PHY_RST		BIT(30)
85 
86 /* PHY register space */
87 
88 /* Offset between lane 0 and lane 1 registers when there are two */
89 #define PHY_LANE_OFFSET				0x0400
90 
91 /* PHY PLL configuration */
92 #define PCIE_PU_ADDR_CLK_CFG			0x0008
93 #define PLL_READY			BIT(0)		/* read-only */
94 #define CFG_INTERNAL_TIMER_ADJ		GENMASK(10, 7)
95 #define TIMER_ADJ_USB		0x2
96 #define TIMER_ADJ_PCIE		0x6
97 #define CFG_SW_PHY_INIT_DONE		BIT(11)	/* We set after PLL config */
98 
99 #define PCIE_RC_DONE_STATUS			0x0018
100 #define CFG_FORCE_RCV_RETRY		BIT(10)		/* Used for PCIe */
101 
102 /* PCIe PHY lane calibration; assumes 24MHz input clock */
103 #define PCIE_RC_CAL_REG2			0x0020
104 #define RC_CAL_TOGGLE			BIT(22)
105 #define CLKSEL				GENMASK(31, 29)
106 #define CLKSEL_24M		0x3
107 
108 /* Additional PHY PLL configuration (USB 3 and PCIe) */
109 #define PCIE_PU_PLL_1				0x0048
110 #define REF_100_WSSC			BIT(12)	/* 1: input is 100MHz, SSC */
111 #define FREF_SEL			GENMASK(15, 13)
112 #define FREF_24M		0x1
113 #define SSC_DEP_SEL			GENMASK(19, 16)
114 #define SSC_DEP_NONE		0x0
115 #define SSC_DEP_5000PPM		0xa
116 
117 /* PCIe PHY configuration */
118 #define PCIE_PU_PLL_2				0x004c
119 #define GEN_REF100			BIT(4)	/* 1: generate 100MHz clk */
120 
121 #define PCIE_RX_REG1				0x0050
122 #define EN_RTERM			BIT(3)
123 #define AFE_RTERM_REG			GENMASK(11, 8)
124 
125 #define PCIE_RX_REG2				0x0054
126 #define RX_RTERM_SEL			BIT(5)	/* 0: use AFE_RTERM_REG value */
127 
128 #define PCIE_LTSSM_DIS_ENTRY			0x005c
129 #define CFG_REFCLK_MODE			GENMASK(9, 8)
130 #define RFCLK_MODE_DRIVER	0x1
131 #define OVRD_REFCLK_MODE		BIT(10)	/* 1: use CFG_RFCLK_MODE */
132 
133 #define PCIE_TX_REG1				0x0064
134 #define TX_RTERM_REG			GENMASK(15, 12)
135 #define TX_RTERM_SEL			BIT(25)	/* 1: use TX_RTERM_REG */
136 
137 /* Zeroed for the combo PHY operating in USB mode */
138 #define USB3_TEST_CTRL				0x0068
139 
140 /* PHY calibration values, determined by the combo PHY at probe time */
141 #define PCIE_RCAL_RESULT			0x0084	/* Port A PHY only */
142 #define RTERM_VALUE_RX			GENMASK(3, 0)
143 #define RTERM_VALUE_TX			GENMASK(7, 4)
144 #define R_TUNE_DONE			BIT(10)
145 
146 static u32 k1_phy_rterm = ~0;     /* Invalid initial value */
147 
148 /* Save the RX and TX receiver termination values */
149 static void k1_phy_rterm_set(u32 val)
150 {
151 	k1_phy_rterm = val & (RTERM_VALUE_RX | RTERM_VALUE_TX);
152 }
153 
154 static bool k1_phy_rterm_valid(void)
155 {
156 	/* Valid if no bits outside those we care about are set */
157 	return !(k1_phy_rterm & ~(RTERM_VALUE_RX | RTERM_VALUE_TX));
158 }
159 
160 static u32 k1_phy_rterm_rx(void)
161 {
162 	return FIELD_GET(RTERM_VALUE_RX, k1_phy_rterm);
163 }
164 
165 static u32 k1_phy_rterm_tx(void)
166 {
167 	return FIELD_GET(RTERM_VALUE_TX, k1_phy_rterm);
168 }
169 
170 /* Only the combo PHY has a PMU pointer defined */
171 static bool k1_phy_port_a(struct k1_pcie_phy *k1_phy)
172 {
173 	return !!k1_phy->pmu;
174 }
175 
176 /* The PLL clocks are driven by the external oscillator */
177 static const struct clk_parent_data k1_pcie_phy_data[] = {
178 	{ .fw_name = "refclk", },
179 };
180 
181 static struct k1_pcie_phy *clk_hw_to_k1_phy(struct clk_hw *clk_hw)
182 {
183 	return container_of(clk_hw, struct k1_pcie_phy, pll_hw);
184 }
185 
186 /* USB mode only works on the combo PHY, which has only one lane */
187 static void k1_pcie_phy_pll_prepare_usb(struct k1_pcie_phy *k1_phy)
188 {
189 	void __iomem *regs = k1_phy->regs;
190 	u32 val;
191 
192 	val = readl(regs + PCIE_PU_ADDR_CLK_CFG);
193 	val &= ~CFG_INTERNAL_TIMER_ADJ;
194 	val |= FIELD_PREP(CFG_INTERNAL_TIMER_ADJ, TIMER_ADJ_USB);
195 	writel(val, regs + PCIE_PU_ADDR_CLK_CFG);
196 
197 	val = readl(regs + PCIE_PU_PLL_1);
198 	val &= ~SSC_DEP_SEL;
199 	val |= FIELD_PREP(SSC_DEP_SEL, SSC_DEP_5000PPM);
200 	writel(val, regs + PCIE_PU_PLL_1);
201 }
202 
203 /* Perform PCIe-specific register updates before starting the PLL clock */
204 static void k1_pcie_phy_pll_prepare_pcie(struct k1_pcie_phy *k1_phy)
205 {
206 	void __iomem *regs = k1_phy->regs;
207 	u32 val;
208 	u32 i;
209 
210 	for (i = 0; i < k1_phy->pcie_lanes; i++) {
211 		val = readl(regs + PCIE_PU_ADDR_CLK_CFG);
212 		val &= ~CFG_INTERNAL_TIMER_ADJ;
213 		val |= FIELD_PREP(CFG_INTERNAL_TIMER_ADJ, TIMER_ADJ_PCIE);
214 		writel(val, regs + PCIE_PU_ADDR_CLK_CFG);
215 
216 		regs += PHY_LANE_OFFSET;	/* Next lane */
217 	}
218 
219 	regs = k1_phy->regs;
220 	val = readl(regs + PCIE_RC_DONE_STATUS);
221 	val |= CFG_FORCE_RCV_RETRY;
222 	writel(val, regs + PCIE_RC_DONE_STATUS);
223 
224 	val = readl(regs + PCIE_PU_PLL_1);
225 	val &= ~SSC_DEP_SEL;
226 	val |= FIELD_PREP(SSC_DEP_SEL, SSC_DEP_NONE);
227 	writel(val, regs + PCIE_PU_PLL_1);
228 
229 	val = readl(regs + PCIE_PU_PLL_2);
230 	val |= GEN_REF100;		/* Enable 100 MHz PLL output clock */
231 	writel(val, regs + PCIE_PU_PLL_2);
232 }
233 
234 static int k1_pcie_phy_pll_prepare(struct clk_hw *clk_hw)
235 {
236 	struct k1_pcie_phy *k1_phy = clk_hw_to_k1_phy(clk_hw);
237 	void __iomem *regs = k1_phy->regs;
238 	u32 val;
239 	u32 i;
240 
241 	if (k1_phy_port_a(k1_phy) && k1_phy->type == PHY_TYPE_USB3)
242 		k1_pcie_phy_pll_prepare_usb(k1_phy);
243 	else
244 		k1_pcie_phy_pll_prepare_pcie(k1_phy);
245 
246 	/*
247 	 * Disable 100 MHz input reference with spread-spectrum
248 	 * clocking and select the 24 MHz clock input frequency
249 	 */
250 	val = readl(regs + PCIE_PU_PLL_1);
251 	val &= ~REF_100_WSSC;
252 	val &= ~FREF_SEL;
253 	val |= FIELD_PREP(FREF_SEL, FREF_24M);
254 	writel(val, regs + PCIE_PU_PLL_1);
255 
256 	/* Mark PLL configuration done on all lanes */
257 	for (i = 0; i < k1_phy->pcie_lanes; i++) {
258 		val = readl(regs + PCIE_PU_ADDR_CLK_CFG);
259 		val |= CFG_SW_PHY_INIT_DONE;
260 		writel(val, regs + PCIE_PU_ADDR_CLK_CFG);
261 
262 		regs += PHY_LANE_OFFSET;	/* Next lane */
263 	}
264 
265 	/*
266 	 * Wait for indication the PHY PLL is locked.  Lanes for ports
267 	 * B and C share a PLL, so it's enough to sample just lane 0.
268 	 */
269 	return readl_poll_timeout(k1_phy->regs + PCIE_PU_ADDR_CLK_CFG,
270 				  val, val & PLL_READY,
271 				  POLL_DELAY, PLL_TIMEOUT);
272 }
273 
274 /* Prepare implies enable, and once enabled, it's always on */
275 static const struct clk_ops k1_pcie_phy_pll_ops = {
276 	.prepare	= k1_pcie_phy_pll_prepare,
277 };
278 
279 /* We represent the PHY PLL as a private clock */
280 static int k1_pcie_phy_pll_setup(struct k1_pcie_phy *k1_phy)
281 {
282 	struct clk_hw *hw = &k1_phy->pll_hw;
283 	struct device *dev = k1_phy->dev;
284 	struct clk_init_data init = { };
285 	char *name;
286 	int ret;
287 
288 	name = kasprintf(GFP_KERNEL, "pcie%u_phy_pll", k1_phy->phy->id);
289 	if (!name)
290 		return -ENOMEM;
291 
292 	init.name = name;
293 	init.ops = &k1_pcie_phy_pll_ops;
294 	init.parent_data = k1_pcie_phy_data;
295 	init.num_parents = ARRAY_SIZE(k1_pcie_phy_data);
296 
297 	hw->init = &init;
298 
299 	ret = devm_clk_hw_register(dev, hw);
300 
301 	kfree(name);	/* __clk_register() duplicates the name we provide */
302 
303 	if (ret)
304 		return ret;
305 
306 	k1_phy->pll = devm_clk_hw_get_clk(dev, hw, "pll");
307 	if (IS_ERR(k1_phy->pll))
308 		return PTR_ERR(k1_phy->pll);
309 
310 	return 0;
311 }
312 
313 /* Select PCIe or USB 3 mode for the combo PHY. */
314 static void k1_combo_phy_sel(struct k1_pcie_phy *k1_phy, bool usb)
315 {
316 	struct regmap *pmu = k1_phy->pmu;
317 
318 	/* Only change it if it's not already in the desired state */
319 	if (!regmap_test_bits(pmu, PMUA_USB_PHY_CTRL0, COMBO_PHY_SEL) == usb)
320 		regmap_assign_bits(pmu, PMUA_USB_PHY_CTRL0, COMBO_PHY_SEL, usb);
321 }
322 
323 static void k1_pcie_phy_init_pcie(struct k1_pcie_phy *k1_phy)
324 {
325 	u32 rx_rterm = k1_phy_rterm_rx();
326 	u32 tx_rterm = k1_phy_rterm_tx();
327 	void __iomem *regs;
328 	u32 val;
329 	int i;
330 
331 	/* For the combo PHY, set PHY to PCIe mode */
332 	if (k1_phy_port_a(k1_phy))
333 		k1_combo_phy_sel(k1_phy, false);
334 
335 	regs = k1_phy->regs;
336 	for (i = 0; i < k1_phy->pcie_lanes; i++) {
337 		val = readl(regs + PCIE_RX_REG1);
338 
339 		/* Set RX analog front-end receiver termination value */
340 		val &= ~AFE_RTERM_REG;
341 		val |= FIELD_PREP(AFE_RTERM_REG, rx_rterm);
342 
343 		/* And enable refclock receiver termination */
344 		val |= EN_RTERM;
345 		writel(val, regs + PCIE_RX_REG1);
346 
347 		val = readl(regs + PCIE_RX_REG2);
348 		/* Use PCIE_RX_REG1 AFE_RTERM_REG value */
349 		val &= ~RX_RTERM_SEL;
350 		writel(val, regs + PCIE_RX_REG2);
351 
352 		val = readl(regs + PCIE_TX_REG1);
353 
354 		/* Set TX driver termination value */
355 		val &= ~TX_RTERM_REG;
356 		val |= FIELD_PREP(TX_RTERM_REG, tx_rterm);
357 
358 		/* Use PCIE_TX_REG1 TX_RTERM_REG value */
359 		val |= TX_RTERM_SEL;
360 		writel(val, regs + PCIE_TX_REG1);
361 
362 		/* Set the input clock to 24 MHz, and clear RC_CAL_TOGGLE */
363 		val = readl(regs + PCIE_RC_CAL_REG2);
364 		val &= CLKSEL;
365 		val |= FIELD_PREP(CLKSEL, CLKSEL_24M);
366 		val &= ~RC_CAL_TOGGLE;
367 		writel(val, regs + PCIE_RC_CAL_REG2);
368 
369 		/* Now trigger recalibration by setting RC_CAL_TOGGLE again */
370 		val |= RC_CAL_TOGGLE;
371 		writel(val, regs + PCIE_RC_CAL_REG2);
372 
373 		val = readl(regs + PCIE_LTSSM_DIS_ENTRY);
374 		/* Override the reference clock; set to refclk driver mode */
375 		val |= OVRD_REFCLK_MODE;
376 		val &= ~CFG_REFCLK_MODE;
377 		val |= FIELD_PREP(CFG_REFCLK_MODE, RFCLK_MODE_DRIVER);
378 		writel(val, regs + PCIE_LTSSM_DIS_ENTRY);
379 
380 		regs += PHY_LANE_OFFSET;	/* Next lane */
381 	}
382 }
383 
384 /* Only called for combo PHY */
385 static void k1_pcie_phy_init_usb(struct k1_pcie_phy *k1_phy)
386 {
387 	k1_combo_phy_sel(k1_phy, true);
388 
389 	/* We're not doing any testing */
390 	writel(0, k1_phy->regs + USB3_TEST_CTRL);
391 }
392 
393 static int k1_pcie_phy_init(struct phy *phy)
394 {
395 	struct k1_pcie_phy *k1_phy = phy_get_drvdata(phy);
396 
397 	/* Note: port type is only valid for port A (both checks needed) */
398 	if (k1_phy_port_a(k1_phy) && k1_phy->type == PHY_TYPE_USB3)
399 		k1_pcie_phy_init_usb(k1_phy);
400 	else
401 		k1_pcie_phy_init_pcie(k1_phy);
402 
403 
404 	return clk_prepare_enable(k1_phy->pll);
405 }
406 
407 static int k1_pcie_phy_exit(struct phy *phy)
408 {
409 	struct k1_pcie_phy *k1_phy = phy_get_drvdata(phy);
410 
411 	clk_disable_unprepare(k1_phy->pll);
412 
413 	return 0;
414 }
415 
416 static const struct phy_ops k1_pcie_phy_ops = {
417 	.init		= k1_pcie_phy_init,
418 	.exit		= k1_pcie_phy_exit,
419 	.owner		= THIS_MODULE,
420 };
421 
422 /*
423  * Get values needed for calibrating PHYs operating in PCIe mode.  Only
424  * the combo PHY is able to do this, and its calibration values are used
425  * for configuring all PCIe PHYs.
426  *
427  * We always need to de-assert the "global" reset on the combo PHY,
428  * because the USB driver depends on it.  If used for PCIe, that driver
429  * will (also) de-assert this, but by leaving it de-asserted for the
430  * combo PHY, the USB driver doesn't have to do this.  Note: although
431  * SpacemiT refers to this as the global reset, we name the "phy" reset.
432  *
433  * In addition, we guarantee the APP_HOLD_PHY_RESET bit is clear for the
434  * combo PHY, so the USB driver doesn't have to manage that either.  The
435  * PCIe driver is free to change this bit for normal operation.
436  *
437  * Calibration only needs to be done once.  It's possible calibration has
438  * already completed (e.g., it might have happened in the boot loader, or
439  * -EPROBE_DEFER might result in this function being called again).  So we
440  * check that early too, to avoid doing it more than once.
441  *
442  * Otherwise we temporarily power up the PHY using the PCIe app clocks
443  * and resets, wait for the hardware to indicate calibration is done,
444  * grab the value, then shut the PHY down again.
445  */
446 static int k1_pcie_combo_phy_calibrate(struct k1_pcie_phy *k1_phy)
447 {
448 	struct reset_control_bulk_data resets[] = {
449 		{ .id = "dbi", },
450 		{ .id = "mstr", },
451 		{ .id = "slv", },
452 	};
453 	struct clk_bulk_data clocks[] = {
454 		{ .id = "dbi", },
455 		{ .id = "mstr", },
456 		{ .id = "slv", },
457 	};
458 	struct device *dev = k1_phy->dev;
459 	int ret = 0;
460 	int val;
461 
462 	/* Nothing to do if we already set the receiver termination value */
463 	if (k1_phy_rterm_valid())
464 		return 0;
465 
466 	/*
467 	 * We also guarantee the APP_HOLD_PHY_RESET bit is clear.  We can
468 	 * leave this bit clear even if an error happens below.
469 	 */
470 	regmap_assign_bits(k1_phy->pmu, PCIE_CLK_RES_CTRL,
471 			   PCIE_APP_HOLD_PHY_RST, false);
472 
473 	/* If the calibration already completed (e.g. by U-Boot), we're done */
474 	val = readl(k1_phy->regs + PCIE_RCAL_RESULT);
475 	if (val & R_TUNE_DONE)
476 		goto out_tune_done;
477 
478 	/* Put the PHY into PCIe mode */
479 	k1_combo_phy_sel(k1_phy, false);
480 
481 	/* Get and enable the PCIe app clocks */
482 	ret = clk_bulk_get(dev, ARRAY_SIZE(clocks), clocks);
483 	if (ret < 0)
484 		goto out_tune_done;
485 	ret = clk_bulk_prepare_enable(ARRAY_SIZE(clocks), clocks);
486 	if (ret)
487 		goto out_put_clocks;
488 
489 	/* Get the PCIe application resets (not the PHY reset) */
490 	ret = reset_control_bulk_get_shared(dev, ARRAY_SIZE(resets), resets);
491 	if (ret)
492 		goto out_disable_clocks;
493 
494 	/* De-assert the PCIe application resets */
495 	ret = reset_control_bulk_deassert(ARRAY_SIZE(resets), resets);
496 	if (ret)
497 		goto out_put_resets;
498 
499 	/*
500 	 * This is the core activity here.  Wait for the hardware to
501 	 * signal that it has completed calibration/tuning.  Once it
502 	 * has, the register value will contain the values we'll
503 	 * use to configure PCIe PHYs.
504 	 */
505 	ret = readl_poll_timeout(k1_phy->regs + PCIE_RCAL_RESULT,
506 				 val, val & R_TUNE_DONE,
507 				 POLL_DELAY, CALIBRATION_TIMEOUT);
508 
509 	/* Clean up.  We're done with the resets and clocks */
510 	reset_control_bulk_assert(ARRAY_SIZE(resets), resets);
511 out_put_resets:
512 	reset_control_bulk_put(ARRAY_SIZE(resets), resets);
513 out_disable_clocks:
514 	clk_bulk_disable_unprepare(ARRAY_SIZE(clocks), clocks);
515 out_put_clocks:
516 	clk_bulk_put(ARRAY_SIZE(clocks), clocks);
517 out_tune_done:
518 	/* If we got the value without timing out, set k1_phy_rterm */
519 	if (!ret)
520 		k1_phy_rterm_set(val);
521 
522 	return ret;
523 }
524 
525 static struct phy *
526 k1_pcie_combo_phy_xlate(struct device *dev, const struct of_phandle_args *args)
527 {
528 	struct k1_pcie_phy *k1_phy = dev_get_drvdata(dev);
529 	u32 type;
530 
531 	/* The argument specifying the PHY mode is required */
532 	if (args->args_count != 1)
533 		return ERR_PTR(-EINVAL);
534 
535 	/* We only support PCIe and USB 3 mode */
536 	type = args->args[0];
537 	if (type != PHY_TYPE_PCIE && type != PHY_TYPE_USB3)
538 		return ERR_PTR(-EINVAL);
539 
540 	/* This PHY can only be used once */
541 	if (k1_phy->type != PHY_NONE)
542 		return ERR_PTR(-EBUSY);
543 
544 	k1_phy->type = type;
545 
546 	return k1_phy->phy;
547 }
548 
549 /* Use the maximum number of PCIe lanes unless limited by device tree */
550 static u32 k1_pcie_num_lanes(struct k1_pcie_phy *k1_phy, bool port_a)
551 {
552 	struct device *dev = k1_phy->dev;
553 	u32 count = 0;
554 	u32 max;
555 	int ret;
556 
557 	ret = of_property_read_u32(dev_of_node(dev), "num-lanes", &count);
558 	if (count == 1)
559 		return 1;
560 
561 	if (count == 2 && !port_a)
562 		return 2;
563 
564 	max = port_a ? 1 : 2;
565 	if (ret != -EINVAL)
566 		dev_warn(dev, "bad lane count %u for port; using %u\n",
567 			 count, max);
568 
569 	return max;
570 }
571 
572 static int k1_pcie_combo_phy_probe(struct k1_pcie_phy *k1_phy)
573 {
574 	struct device *dev = k1_phy->dev;
575 	struct regmap *regmap;
576 	int ret;
577 
578 	/* Setting the PHY mode requires access to the PMU regmap */
579 	regmap = syscon_regmap_lookup_by_phandle(dev_of_node(dev), SYSCON_APMU);
580 	if (IS_ERR(regmap))
581 		return dev_err_probe(dev, PTR_ERR(regmap), "failed to get PMU\n");
582 	k1_phy->pmu = regmap;
583 
584 	ret = k1_pcie_combo_phy_calibrate(k1_phy);
585 	if (ret)
586 		return dev_err_probe(dev, ret, "calibration failed\n");
587 
588 	/* Needed by k1_pcie_combo_phy_xlate(), which also sets k1_phy->type */
589 	dev_set_drvdata(dev, k1_phy);
590 
591 	return 0;
592 }
593 
594 static int k1_pcie_phy_probe(struct platform_device *pdev)
595 {
596 	struct phy *(*xlate)(struct device *dev,
597 			     const struct of_phandle_args *args);
598 	struct device *dev = &pdev->dev;
599 	struct reset_control *phy_reset;
600 	struct phy_provider *provider;
601 	struct k1_pcie_phy *k1_phy;
602 	bool probing_port_a;
603 	int ret;
604 
605 	xlate = of_device_get_match_data(dev);
606 	probing_port_a = xlate == k1_pcie_combo_phy_xlate;
607 
608 	/* Only the combo PHY can calibrate, so it must probe first */
609 	if (!k1_phy_rterm_valid() && !probing_port_a)
610 		return -EPROBE_DEFER;
611 
612 	k1_phy = devm_kzalloc(dev, sizeof(*k1_phy), GFP_KERNEL);
613 	if (!k1_phy)
614 		return -ENOMEM;
615 	k1_phy->dev = dev;
616 
617 	k1_phy->regs = devm_platform_ioremap_resource(pdev, 0);
618 	if (IS_ERR(k1_phy->regs))
619 		return dev_err_probe(dev, PTR_ERR(k1_phy->regs),
620 				     "error mapping registers\n");
621 
622 	/* De-assert the PHY (global) reset and leave it that way */
623 	phy_reset = devm_reset_control_get_exclusive_deasserted(dev, "phy");
624 	if (IS_ERR(phy_reset))
625 		return PTR_ERR(phy_reset);
626 
627 	if (probing_port_a) {
628 		ret = k1_pcie_combo_phy_probe(k1_phy);
629 		if (ret)
630 			return dev_err_probe(dev, ret,
631 					     "error probing combo phy\n");
632 	}
633 
634 	k1_phy->pcie_lanes = k1_pcie_num_lanes(k1_phy, probing_port_a);
635 
636 	k1_phy->phy = devm_phy_create(dev, NULL, &k1_pcie_phy_ops);
637 	if (IS_ERR(k1_phy->phy))
638 		return dev_err_probe(dev, PTR_ERR(k1_phy->phy),
639 				     "error creating phy\n");
640 	phy_set_drvdata(k1_phy->phy, k1_phy);
641 
642 	ret = k1_pcie_phy_pll_setup(k1_phy);
643 	if (ret)
644 		return dev_err_probe(dev, ret, "error initializing clock\n");
645 
646 	provider = devm_of_phy_provider_register(dev, xlate);
647 	if (IS_ERR(provider))
648 		return dev_err_probe(dev, PTR_ERR(provider),
649 				     "error registering provider\n");
650 	return 0;
651 }
652 
653 static const struct of_device_id k1_pcie_phy_of_match[] = {
654 	{ .compatible = "spacemit,k1-combo-phy", k1_pcie_combo_phy_xlate, },
655 	{ .compatible = "spacemit,k1-pcie-phy", of_phy_simple_xlate, },
656 	{ },
657 };
658 MODULE_DEVICE_TABLE(of, k1_pcie_phy_of_match);
659 
660 static struct platform_driver k1_pcie_phy_driver = {
661 	.probe	= k1_pcie_phy_probe,
662 	.driver = {
663 		.of_match_table	= k1_pcie_phy_of_match,
664 		.name = "spacemit-k1-pcie-phy",
665 	}
666 };
667 module_platform_driver(k1_pcie_phy_driver);
668 
669 MODULE_DESCRIPTION("SpacemiT K1 PCIe and USB 3 PHY driver");
670 MODULE_LICENSE("GPL");
671